Brain tumors are one of the most, if not the most, difficult problems in cancer. There is only one known cause, high doses of radiation used to treat other malignancies, and that cause only accounts for less than 1% of brain tumors. Since so little is known of the cause, there is no effective prevention, and there are no tests for early detection, such as exist for breast, cervical, and prostate cancer. Treatment is toxic and ineffective. Surgery is limited by the inability to remove areas of the brain involved by tumor that control speech, personality, memory, and movement. Radiation destroys normal brain over time and impairs memory function. Most drugs are ineffective and no drugs more effective than those introduced in the 1970s have been developed. The most efficient way to attack a complex and challenging clinical problem is to achieve a critical mass of scientists, clinicians, and physician-scientists in an institutional setting. This allows exploration of the problem from the most basic level to the most applied clinical level with communication and cross-fertilization within the institution, providing scientists with an understanding of important clinical issues and clinicians with access to the newest scientific advances and potential therapeutic approaches. The critical link in this model is the physician-scientist who has clinical expertise and focused scientific training in an area relevant to the clinical problem. These individuals are likely to become the academic leaders of the next generation in their field. There are very few divisions of pediatric hematology/ oncology with a committed neuro-oncologist. Furthermore, there are only rare adult neuro-oncology programs which seek to train physician-scientists in neuro-oncology and there are only a handful of adult neuro-oncologists conducting both major laboratory and clinical investigations. This lack of physician-scientists in adult and pediatric neuro-oncology is a major impediment as detailed above to conducting translational research designed to advance the therapy of adults and children with brain rumors. This T32 application is designed to continue to train new adult and pediatric neuro-oncology [unreadable] physician-scientists who can lead future efforts in translational research in this field. [unreadable] [unreadable] [unreadable]